124' Mr. Lubbock on the Tides in the Fori of London. 



Type. Sf.si A Apiformis — Ichncnmoniformis — Vespiformis. 

 19 Species. 



46. Amata. — Mouth with projecting laminae, the labia co- 

 vered by the base of the maxillae. Palpi very short, with 

 only a single joint. Antennce setiform. 



Type. Zyg^na Passalis — Cerhera. 



^1. Zyg^na. — Palpi biarticulate ; second joint longer, very 

 pilose externally. Antennce incrassate in the middle. 

 Type. TiYCi. Filipendidce — Scabiosce — Qtiercns. 17 Species. 



48. Glaxjcopis. — Palpi long, recurved, triarticulate; second 

 joint longer, externally pilose ; third joint compressed, 

 naked. Antennce setiform, pectinated. 



Type. Zyg. A7-gynnis — Pugione — Halter at a — hifausta. 

 65 Species. 



49. Procris. — Palpi two, slendej', recurved, arched, triarti- 

 culate ; joints nearly equal. Antemicc cylindrical. 



Type. Zyg. Statices — Pruni. 9 Species. 



Illiger add« that the following species, which are contained 

 in an appendix, were not referred by Fabricius to any of his 

 new genera : — Papilio Cencetis — Chr ernes — Hesperus — Mirus 

 — Pentheus — Darius — Dcvdalus — Polymcnus — Nerina. 

 [Communicated by J. G. Children, Esq. F.R.S. &c.] 



XVII. On the Tides in the Port of London. By John Wilt.iam 

 Lubbock, Esq. F.R.S. Sf L.S.* 



¥N the Companion to the British Almanac for 1830, I have 

 published a disquisition on the tides, in which I have en- 

 deavoured to show the connection between the theory of the 

 tides and the facts as they are observed in the Thames at Lon- 

 don. M. Bouvard compared the observations made at Brest 

 with the results of Laplace's theory; but no other comparison 

 of the kind has ever been instituted ; which is highly remark- 

 able in the instanceof a phaenomenon which is of daily occur- 

 rence and striking regularity, and where a vast mechanical 

 power is perpetually exerted before our eyes. The tide-tables 

 which have hitherto been published in this country, have been 

 calculated by methods which are studiously kept secret. The 

 first attempt, however, which has been made to reconcile theory 

 with observation has j^'oduced tide-tables which will, I believe, 

 be found as accurate as any of those calculated by empirical 

 niles long tried, and probably often corrected. 



Coiiiinunicalfil liy the Author. 



I believe 



